What is the significance of methemoglobin in the context of oxygen transport?

A It is a form of hemoglobin that has a higher affinity for oxygen
B It is a form of hemoglobin that is unable to bind oxygen
C It is a form of hemoglobin that has been oxidized and is unable to transport oxygen ✓
D It is a form of hemoglobin that is involved in the transport of carbon dioxide

Explanation

Methemoglobin is a form of hemoglobin that has been oxidized, resulting in the loss of its ability to transport oxygen. It can be reduced back to its normal state by enzymes such as methemoglobin reductase.

Source

Robbins and Cotran Pathologic Basis of Disease
Hematology Hematology: Hemoglobin and Oxygen Transport Hematology: Hemoglobin and Oxygen Transport Medium MEDICAL Confidence: high